title: Formation of omega- and (omega-1)-hydroxyfatty acids and plausible formation of ketofatty acid from microsomal phospholipids.
abstract: Rat liver microsomes labeled with spin-labeled phosphatidylcholine release the label into the aqueous phase during the aerobic incubation with NADPH (Biochem. Biophys. Res. Commun. (1979) 87, 300-307). To establish the chemical nature of the released moiety, microsomes were labeled with [14C]phosphatidylcholine. When the 14C-labeled microsomes were incubated with NADPH under aerobic conditions, a few percent of the radioactivity was liberated into the aqueous phase within 60 min. Thin-layer chromatographic analysis of the radioactive substance liberated showed the presence of hydroxylated fatty acids derived from the 2-position of glycerol moiety. About one-third of the fatty acids formed from [14C]phosphatidylcholine during the incubation were converted into hydroxy-derivatives. Gas chromatography/mass spectrometry analysis further confirmed an NADPH-dependent formation of 16-hydroxypalmitic acid, 15-hydroxypalmitic acid, and hydroxy-derivatives of other fatty acids from the phospholipids of the microsomal membrane. Evidence was also obtained indicating the formation of ketopalmitic acid.
mesh_terms: D000818:Animals; D008401:Gas Chromatography-Mass Spectrometry; D006880:Hydroxy Acids / Q000096:biosynthesis*; D007553:Isotope Labeling; D007651:Keto Acids / Q000096:biosynthesis*; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism*; D051381:Rats
chemical_list: D006880:Hydroxy Acids; D007651:Keto Acids; D010713:Phosphatidylcholines; D009249:NADP